Silverlight 4: How to programmatically position a control within a Grid

<UserControl x:Class="SetGridProgrammatically.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">

    <Grid x:Name="LayoutRoot" Background="White" ShowGridLines="True">
        <Grid.RowDefinitions>
            <RowDefinition Height="93*" />
            <RowDefinition Height="70*" />
            <RowDefinition Height="137*" />
        Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="70*" />
            <ColumnDefinition Width="182*" />
            <ColumnDefinition Width="148*" />
        Grid.ColumnDefinitions>
    Grid>
UserControl>

```text
```csharp

Button b = new Button();

b.Content = "Silverlight";
LayoutRoot.Children.Add(b);

b.SetValue(Grid.RowProperty, 1);
b.SetValue(Grid.ColumnProperty, 1);